全文获取类型
收费全文 | 3252761篇 |
免费 | 254269篇 |
国内免费 | 6293篇 |
专业分类
耳鼻咽喉 | 48199篇 |
儿科学 | 100261篇 |
妇产科学 | 89273篇 |
基础医学 | 455699篇 |
口腔科学 | 96359篇 |
临床医学 | 291772篇 |
内科学 | 632969篇 |
皮肤病学 | 69115篇 |
神经病学 | 269746篇 |
特种医学 | 129361篇 |
外国民族医学 | 1251篇 |
外科学 | 495563篇 |
综合类 | 78306篇 |
现状与发展 | 7篇 |
一般理论 | 1320篇 |
预防医学 | 253562篇 |
眼科学 | 78423篇 |
药学 | 244420篇 |
8篇 | |
中国医学 | 6365篇 |
肿瘤学 | 171344篇 |
出版年
2018年 | 31790篇 |
2016年 | 27354篇 |
2015年 | 30838篇 |
2014年 | 44288篇 |
2013年 | 67705篇 |
2012年 | 90402篇 |
2011年 | 95526篇 |
2010年 | 56348篇 |
2009年 | 54417篇 |
2008年 | 91164篇 |
2007年 | 97741篇 |
2006年 | 98669篇 |
2005年 | 96300篇 |
2004年 | 92819篇 |
2003年 | 89919篇 |
2002年 | 88852篇 |
2001年 | 149700篇 |
2000年 | 154820篇 |
1999年 | 131279篇 |
1998年 | 37422篇 |
1997年 | 34102篇 |
1996年 | 33255篇 |
1995年 | 32140篇 |
1994年 | 30109篇 |
1993年 | 28033篇 |
1992年 | 105053篇 |
1991年 | 101405篇 |
1990年 | 98422篇 |
1989年 | 95265篇 |
1988年 | 88504篇 |
1987年 | 87245篇 |
1986年 | 83106篇 |
1985年 | 79397篇 |
1984年 | 60059篇 |
1983年 | 51154篇 |
1982年 | 31091篇 |
1981年 | 27857篇 |
1980年 | 26133篇 |
1979年 | 56880篇 |
1978年 | 40256篇 |
1977年 | 34426篇 |
1976年 | 31834篇 |
1975年 | 34550篇 |
1974年 | 41992篇 |
1973年 | 40234篇 |
1972年 | 38070篇 |
1971年 | 35471篇 |
1970年 | 33489篇 |
1969年 | 31436篇 |
1968年 | 28915篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
Anuj Shrestha Zeeshan Jawa Kathryn L. Koch Amy B. Rankin Qun Xiang Anand Padmanabhan Matthew S. Karafin Joshua J. Field 《Journal of clinical apheresis》2015,30(6):353-358
Red cell exchange (RCE) is a common procedure in adults with sickle cell disease (SCD). Implantable dual lumen Vortex (DLV) ports can be used for RCE in patients with poor peripheral venous access. We performed a retrospective cohort study of RCE procedures performed in adults with SCD. The main objective of the study was to compare the inlet speed, duration of procedures and rate of complications performed through DLV ports to those performed through temporary central venous and peripheral catheters. Twenty‐nine adults with SCD underwent a total of 318 RCE procedures. Twenty adults had DLV ports placed and 218 procedures were performed using DLV ports. Mean length of follow‐up after DLV port placement was 397 ± 263 days. Six DLV ports were removed due to infection and 1 for malfunction after a mean of 171 ± 120 days. Compared to temporary central venous and peripheral catheters, DLV port procedures had a greater rate of procedural complications, a longer duration, and a lower inlet speed (all P < 0.01). When accounting for the maximum allowable inlet speed to avoid citrate toxicity, 40% of DLV port procedures were greater than 10% below maximum speed, compared to 7 and 14% of procedures performed through temporary central venous and peripheral catheters (P < 0.0001). In conclusion, DLV ports can be used for RCE in adults with SCD, albeit with more procedural complications and longer duration. The smaller internal diameter and longer catheter of DLV ports compared to temporary central venous catheters likely accounts for the differences noted. J. Clin. Apheresis 30:353–358, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
94.
95.
Emma J. Kilford Iroise Dumontheil Nicholas W. Wood Sarah-Jayne Blakemore 《Social cognitive and affective neuroscience》2015,10(6):777-782
The catechol-O-methyltransferase (COMT) enzyme is a major determinant of prefrontal dopamine levels. The Val158Met polymorphism affects COMT enzymatic activity and has been associated with variation in executive function and affective processing. This study investigated the effect of COMT genotype on the flexible modulation of the balance between processing self-generated and processing stimulus-oriented information, in the presence or absence of affective distractors. Analyses included 124 healthy adult participants, who were also assessed on standard working memory (WM) tasks. Relative to Val carriers, Met homozygotes made fewer errors when selecting and manipulating self-generated thoughts. This effect was partly accounted for by an association between COMT genotype and visuospatial WM performance. We also observed a complex interaction between the influence of affective distractors, COMT genotype and sex on task accuracy: male, but not female, participants showed a sensitivity to the affective distractors that was dependent on COMT genotype. This was not accounted for by WM performance. This study provides novel evidence of the role of dopaminergic genetic variation on the ability to select and manipulate self-generated thoughts. The results also suggest sexually dimorphic effects of COMT genotype on the influence of affective distractors on executive function. 相似文献
96.
97.
98.
99.
100.
E. Niclas Jonsson Rujia Xie Scott F. Marshall Rosalin H. Arends 《British journal of clinical pharmacology》2016,81(4):688-699
AimsThe aims were to 1) develop the pharmacokinetics model to describe and predict observed tanezumab concentrations over time, 2) test possible covariate parameter relationships that could influence clearance and distribution and 3) assess the impact of fixed dosing vs. a dosing regimen adjusted by body weight.MethodsIndividual concentration–time data were determined from 1608 patients in four phase 3 studies conducted to assess efficacy and safety of intravenous tanezumab. Patients received two or three intravenous doses (2.5, 5 or 10 mg) every 8 weeks. Blood samples for assessment of tanezumab PK were collected at baseline, 1 h post‐dose and at weeks 4, 8, 16 and 24 (or early termination) in all studies. Blood samples were collected at week 32 in two studies. Plasma samples were analyzed using a sensitive, specific, validated enzyme‐linked immunosorbent assay.ResultsA two compartment model with parallel linear and non‐linear elimination processes adequately described the data. Population estimates for clearance (CL), central volume (V
1), peripheral volume (V
2), inter‐compartmental clearance, maximum elimination capacity (VM) and concentration at half‐maximum elimination capacity were 0.135 l day–1, 2.71 l, 1.98 l, 0.371 l day–1, 8.03 μg day–1 and 27.7 ng ml–1, respectively. Inter‐individual variability (IIV) was included on CL, V
1, V
2 and VM. A mixture model accounted for the distribution of residual error. While gender, dose and creatinine clearance were significant covariates, only body weight as a covariate of CL, V
1 and V
2 significantly reduced IIV.ConclusionsThe small increase in variability associated with fixed dosing is consistent with other monoclonal antibodies and does not change risk : benefit. 相似文献